About Pityriasis Rosea

Pityriasis rosea is a rash that most physicians and health practitioners encounter frequently among the younger people in the population, primarily during the spring and fall. Because it is possible to mistake pityriasis rosea with other conditions, including eczema and impetigo, tests are sometimes performed to establish a diagnosis. Pityriasis rosea cannot be prevented nor cured and generally resolves without the need for medications.

Signs and Symptoms

"Herald" Patch

Most cases of pityriasis rosea begin with the presence of a reddish, slightly raised, "herald" patch measuring 1-to-2 inches on the torso of an older child to young adult. Approximately 7-to-10 days later, 10 to 100 smaller patches appear on both sides of the trunk; the spots on the back settle along the skin creases, forming a cone-shaped or fir-tree pattern. In a younger child, a scattering of spots might occur along the arms and legs and, although it is not as common, may also develop on the face, neck and scalp.

Diagnosis

Small bumps with obscure centers

In people with darker skin tones, pityriasis rosea may appear as small, dark, slightly raised pinkish-brown bumps with some scales. In people with lighter coloring, it is characterized by small, scaly, round and oval pink or salmon-colored spots that resemble the fungal infection ringworm. When identification is uncertain, a KOH skin-scraping test is performed on the rash to check for the presence of bacteria. The appearance of a pityriasis rosea rash might also be confused with secondary syphilis. For this reason, the practitioner often orders a blood test to arrive at a definitive diagnosis.

Cause and Effects

Although the cause of pityriasis rosea is not known, a virus is suspected. Virus-like symptoms, including a mild fever, headache, sore throat, aching joints and malaise sometimes occur at the same time the "herald" spot appears. Itching, especially at night, may also occur. The condition is not contagious and it presents no danger to pregnant women or their fetuses.

Time Frame

Pityriasis Rosea usually takes six weeks to run its course

A typical outbreak of pityriasis runs its course in an average of six weeks, presenting in the first two weeks, stabilizing over the next two weeks and coming to a resolution during the last two weeks. Although it is not common, it may take some people longer than six weeks to recover.

Treatment and Resolution

An Oatmeal bath provides relief for itching

Although there is no way to prevent pityriasis, measures can be taken to relieve its symptoms. Relief for itching is available in the form of lotions and creams containing topical anesthetics, cooling agents such as camphor, antihistamines and steroids. An urge to scratch the rash may also be contained by soaking in a tub treated with an oatmeal bath preparation available at drug stores. Patients who are bothered by itching despite the use of these methods might be willing to try ultraviolet light as a last resort.

Considerations for Darker Complexions

Hyperpigmentation may not completely fade for several weeks

For unknown reasons, African Americans sometimes experience the pityriasis rosea rash differently from that of other races. For instance, African Americans tend to develop the rash on their faces, which is uncommon in other races. Other variations in the rash's presentation on dark skin can be seen in the nature of the bumps and their eventual coalescing into oval-shaped patches. It is not unusual for black skin to be show traces of excess pigmentation for several weeks after the pityriasis rosea episode passes.

Insights

Soaps should be avoided during breakouts of pityriasis rosea; instead, oil may be added to the bathwater or mineral oil may be applied to the skin after bathing to soften scaly patches.
The antiviral durg aciclovir may hasten recovery if taken at the onset of a pityriasis rosea infection.
If the infection does not resolve in two months, the possibility that it is not pityriasis rosea should be considered.